In the manufacture of aperture masks the product starts as a roll of 0.007 inch steel of suitable type and undergoes a series of photographic and chemical process steps to produce apertures of the required size and spacing. The last step is to separate the masks from the web which is done with the web in a vertical position. The masks are discharged through a set of pinch rolls with the major axis vertical. The masks are then directed down a chute where they are collected and transported to an inspection area. At prescribed intervals a mask is checked for the amount of light transmitted through the center portion of the mask. If this check indicates a defective mask than all of the masks made since the last passing inspection must be tested. This backlog of masks could be considerable since the masks are made at the rate of about ten per minute. In addition to the inspection load, the process must be changed to prevent further production of defective masks.
In view of the foregoing it is an object of this invention to provide an aperture mask conveyor and inspection system that will be quickly responsive to process variations and thereby greatly cut down on the production of defective masks.
It is another object of this invention to provide a system as set forth in the previous object which is substantially automated.
It is yet another object of this invention to provide a mask conveyor and inspection system which will check every mask in order of production and provide a continuous record of such checks to make it possible to indicate process changes before defects are produced by noting trends in the test results.
The above and additional objects and advantages will become more apparent when taken in conjunction with the following detailed description and drawings.